Metaphysical rationalism, the doctrine which affirms the Principle of Sufficient Reason (the PSR), is out of favor today. The best argument against it is that it appears to lead to necessitarianism, the claim that all truths are necessarily true. Whatever the intuitive appeal of the PSR, the intuitive appeal of the claim that things could have been otherwise is greater. This problem did not go unnoticed by the great metaphysical rationalists Spinoza and Leibniz. Spinoza’s response was to embrace necessitarianism. Leibniz’s (...) response was to argue that, despite appearances, rationalism does not lead to necessitarianism. This paper examines the debate between these two rationalists and concludes that Leibniz has persuasive grounds for his opinion. This has significant implications both for the plausibility of the PSR and for our understanding of modality. (shrink)

In Spinoza’s metaphysics, we encounter many puzzling doctrines that appear to entangle metaphysical notions with cognitive, logical, and epistemic ones. According to him, a substance is that which can be conceived through itself and a mode is that which is conceived through another. Thus, metaphysical notions, substance and mode, are defined through a notion that is either cognitive or logical, being conceived through. He defines an attribute as that which an intellect perceives as constituting the essence of a substance. Intellectual (...) perception, something cognitive, is used to define an attribute, something metaphysical. And he claims that if something exists there is a reason why it exists and if something doesn’t exist there is also a reason why it doesn’t. Thus, a reason, something cognitive or epistemic, is necessary for existence or nonexistence. What are we to make of the intimate connections that Spinoza sees between metaphysical, cognitive, logical, and epistemic notions? Between being and reason? In this book, I argue for what might be called a realist interpretation: although Spinoza is confident that the order of being mirrors the order of reason, he believes that they are two orders, not one. There is inherence over and above conceptual dependence; there is causation in addition to causal explanation; the world has a nature that we can grasp and that our way of grasping it does not interpose an impenetrable conceptual veil between it and us. (shrink)

The Principle of Sufficient Reason is a powerful and controversial philosophical principle stipulating that everything must have a reason or cause. This simple demand for thoroughgoing intelligibility yields some of the boldest and most challenging theses in the history of metaphysics and epistemology. In this entry we begin with explaining the Principle, and then turn to the history of the debates around it. A section on recent discussions of the Principle will be added in the near future.

Cover Date: July 2006.Source Info: 115(3), 317-354. Language: English. Journal Announcement: 41-2. Subject: ACTION; CAUSATION; METAPHYSICS; REPRESENTATION; TELEOLOGY. Subject Person: SPINOZA, BENEDICT DE (BARUCH). Update Code: 20130315.

: Perhaps the central problem which preoccupies Spinoza as a moral philosopher is the conflict between reason and passion. He belongs to a long tradition that sees the key to happiness and virtue as mastery and control by reason over the passions. This mastery, however, is hard won, as the passions often overwhelm its power and subvert its rule. When reason succumbs to passion, we act against our better judgment. Such action is often termed 'akratic'. Many commentators have complained that (...) the psychological principles that Spinoza appeals to in his account of akrasia are mere ad hoc modifications to his philosophical psychology. I show, on the contrary, that these principles follow from some of the most important and interesting aspects of Spinoza's philosophy of mind. (shrink)

Locke is often thought to have introduced the topic of personal identity into philosophy when, in the second edition of theEssay,he distinguished the person from both the human being and the soul. Each of these entities differs from the others with respect to their identity conditions, and so they must be ontologically distinct. In particular, Locke claimed, a person cannot survive total memory loss, although a human being or a soul can.

It is often thought that, although Spinoza develops a bold and distinctive conception of God (the unique substance, or Natura Naturans, in which all else inheres and which possesses infinitely many attributes, including extension), the arguments that he offers which purport to prove God’s existence contribute nothing new to natural theology. Rather, he is seen as just another participant in the seventeenth century revival of the ontological argument initiated by Descartes and taken up by Malebranche and Leibniz among others. That (...) this is the case is both puzzling and unfortunate. It is puzzling because although Spinoza does offer an ontological proof for the existence of God, he also offers three other non‐ontological proofs. It is unfortunate because these other non‐ontological proofs are both more convincing and more interesting than his ontological proof. In this paper, I offer reconstructions and assessments of all of Spinoza’s arguments and argue that Spinoza’s metaphysical rationalism and his commitment to something like a Principle of Sufficient Reason are the driving force behind Spinoza’s non‐ontological arguments. (shrink)

Some of Spinoza's most well‐known doctrines concern what kinds of beings there are and how they are related to each other. For example, he claims that: (1) there is only one substance; (2) this substance has infinitely many attributes; (3) this substance is God or nature; (4) each of these attributes express the divine essence; and (5) all else is a mode of the one substance. These claims have so astonished many of his readers that some of them have surely (...) concluded that they must not know what Spinoza means by “substance,”“attribute,” and “mode.” In this article I shall try to explain how Spinoza understands the basic ontological categories denoted by these expressions. (shrink)

Material from this paper appears in Chap. 7 of my book Reason and Being, but there is also stuff here that isn't in the book. In particular, it discusses the claims that, for Spinoza, conceiving implies explaining and that existence is identical to or reducible to conceivability. So, if you're interested in those issues, this paper might be worth a read.

abstract: Leibniz holds that there are no two perfectly similar things, a doctrine he calls the Principle of the Identity of Indiscernibles (the PII). What is his attitude toward its modal status? Most commentators hold that the principle is best understood as a necessary truth because it is allegedly entailed by doctrines such as the conceptual containment theory of truth, the Principle of Sufficient Reason (the PSR), and the denial of purely extrinsic denominations, which are arguably regarded by Leibniz as (...) necessary truths. In this paper, I argue against this consensus and show that (1) neither the conceptual containment theory of truth, nor the PSR, nor the denial of purely extrinsic denominations give Leibniz a good reason to hold that the PII is necessary; (2) Leibniz says that the PII is contingent in the correspondence with Clarke and not for dialectical reasons; and (3) the argument that Leibniz gives for the PII in §21 of his Fifth Letter to Clarke has been misunderstood; properly interpreted, it gives Leibniz a cogent argument rooted in some of his most important doctrines for the conclusion that the PII is a contingent truth. (shrink)

In this paper, I respond to criticisms of my book Being and Reason recently made by Yitzhak Melamed.